1. Field of the Invention
The present invention relates to a motor control apparatus and a motor control method.
2. Description of the Related Art
Permanent magnet synchronous motors that do not require mechanical parts such as brushes, which become worn, and are compact and highly efficient are utilized widely as drive motors in electric cars and the like. In an ideal permanent magnet synchronous motor, the armature magnetic flux linkage generated by the permanent magnet changes sinusoidally relative to the phase. However, if there is any distortion in the magnetic flux, the vector control normally implemented on the motor current does not effectively prevent the occurrence of torque rippling and deterioration in the motor efficiency attributable to the higher harmonic components of the motor current.
There is a motor control apparatus in the known art that addresses the problem described above by individually controlling the fundamental wave component and the higher harmonic component of the motor current respectively in a dq coordinate system and a dhqh coordinate system that rotate in synchronization with the corresponding current components (see Japanese Laid Open Patent Publication No. 2002-223600)